- stress_rc.lux: Single-owner chains testing FBIP optimization
- stress_shared_rc.lux: Shared-reference chains (rc>1) forcing copy path
Both process lists of 100, 200, 500, and 1000 elements with map/filter/reverse.
Verifies no memory leaks with large data sets.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>